Method of implanting a glenoid assembly

ABSTRACT

A method of implanting a glenoid assembly, includes forming a first bore in a glenoid region of a scapula and inserting a first peg of a glenoid component into the first bore. The method includes plastically deforming a first passageway within the first peg, while the first peg is inserted into the first bore, by inserting a first stiffening pin into the first passageway.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/894,255, filed Jun. 5, 2020, which is a continuation of U.S.application Ser. No. 15/808,258, filed Nov. 9, 2017, entitled “GlenoidComponent for Use in Shoulder Arthroplasty”, which issued Jun. 23, 2020as U.S. Pat. No. 10,687,951, which is a divisional application of U.S.patent application Ser. No. 12/408,391, filed on Mar. 20, 2009 entitled“Glenoid Component for Use in Shoulder Arthroplasty”, which issued Dec.5, 2017 as U.S. Pat. No. 9,833,327, the entire contents of which areeach incorporated herein by reference.

BACKGROUND

The present disclosure relates generally to a glenoid component for ause in a shoulder arthroplasty, and an associated method of implantingthe glenoid component in a scapula of a patient.

It has become common to perform a shoulder arthroplasty to repair apatient's shoulder joint which has become dysfunctional due to diseaseor trauma. During such a procedure, the natural glenoid surface of thescapula is resurfaced or otherwise replaced with a prosthetic glenoidcomponent which provides a bearing surface for a head of the humerus ora head portion of a humeral prosthesis (hereinafter “humeral head”).

Various glenoid components have heretofore been designed to include abase component that defines a bearing surface on a humeral-facing sideand a number of pegs that extend from a scapula-facing side of the basecomponent. These pegs may include relatively long anchor pegs having aplurality of radially extending fins and/or relatively short stabilizingor anti-rotation pegs which may or may not have a series of groovesdefined therein. One example of an existing glenoid component possessingthe above-described configuration is disclosed in U.S. Pat. No.6,911,047, the disclosure which is herein incorporated by reference inits entirety.

The pegs of this type of existing glenoid component extend from thescapula-facing side of the base component so that the axes defined bythe pegs are parallel with respect to each other. One drawback ofglenoid components with parallel oriented pegs is the inability in someinstances to reach healthy bone stock remaining in a patient's scapula.In particular, there are many clinical situations in which a patient'sscapula possesses deficient bone stock at the locations which align withthe relatively long, parallel anchor pegs. Thus, upon implantation ofthe glenoid component, the anchor pegs reside in deficient bone stockthereby causing an unstable attachment of the glenoid component to thepatient's scapula. Interestingly, in many of these clinical situations,healthy bone stock is observed in other locations of the glenoid regionof the scapula.

In order to address this problem, some existing glenoid componentspossess pegs extending from the scapula-facing side of the basecomponent which are divergent with respect to each other. Beingconfigured divergent, the pegs are targeted to be embedded in healthierscapula bone stock for more effective anchoring of the pegs. One exampleof this type of glenoid component is disclosed in U.S. Pat. No.5,593,448 (hereinafter “the '448 patent”).

However, providing the pegs of the glenoid component with a non-parallelorientation (e.g. divergent or convergent) causes some challenges forimplantation of the device. Significantly, during implantation, the pegsof the glenoid component do not physically align with the bores drilledin the scapula for receiving the pegs. In contrast, pegs having aparallel orientation with respect to each other align with drilled boresthereby facilitating implantation of the glenoid component. In order toaddress the implantation challenge of non-parallel peg type glenoidcomponents, the '448 patent teaches that its base component isconfigured to flex or deform so as to cause its pegs to becometemporarily more aligned with the holes defined in the scapula so thatinsertion of the pegs therein is enabled.

There are drawbacks associated with providing a glenoid component havinga readily flexible or deformable base component. Indeed, the basecomponent of a glenoid component, when implanted, receives a significantamount of force during normal use. In particular, the humeral headarticulates against the base component of the glenoid component duringnormal human use. If the base component flexes or deforms when thehumeral head is urged against it, unnatural forces may be applied to thesoft tissue and muscles that interconnect the humerus to the scapula.These unnatural forces may cause damage to such soft tissue and muscles.In addition, pain or discomfort to a person in which the glenoidcomponent is implanted may result due to the unnatural forces.

Additionally, creating a base component of a glenoid component frommaterials that are more flexible or deformable may result in a basecomponent which is less durable in relation to non-flexible ornon-deformable base components (i.e. conventional base components).Thus, during normal use of the shoulder joint, articulation of thehumeral head against the flexible or deformable base component may causerelatively rapid deterioration of the base component thereby resultingin early failure of the glenoid component. Moreover, wear debris may bemore readily generated in such a device.

What is needed therefore is an improved glenoid component that possessesnon-parallel oriented pegs (e.g. diverging or converging pegs). What isalso needed is an improved method of implanting such a glenoid componentin the scapula of a patient. What is further needed is a glenoidcomponent with non-parallel oriented pegs that has a base componentwhich possesses the degree of structural integrity equivalent with basecomponents of conventional glenoid components. What is additionallyneeded is a glenoid component having non parallel oriented pegs that hasa base component that does not flex or deform significantly duringarticulation of a humeral head there-against. What is also need is aglenoid component having non parallel oriented pegs that do not generatesignificant wear debris during articulation of a humeral headthere-against. What is further needed is a glenoid component having nonparallel oriented pegs that do not cause unnatural forces to be appliedto the soft tissue and muscles that interconnect the humerus to thescapula during articulation of the humeral head against the basecomponent of the glenoid component. What is further needed is a glenoidcomponent having non parallel oriented pegs that do not cause damage tosuch soft tissue and muscles that interconnect the humerus to thescapula during articulation of the humeral head against the basecomponent of the glenoid component. What is also needed is a glenoidcomponent having non parallel oriented pegs that does not cause pain ordiscomfort to a patient in which the glenoid component is implantedduring articulation of the humeral head against the base component ofthe glenoid component. Additional features and advantages of the presentdisclosure will become apparent to those skilled in the art uponconsideration of the following detailed description of the preferredembodiments.

SUMMARY

In accordance with one embodiment of the present disclosure, there isprovided a glenoid assembly. The glenoid assembly includes a basecomponent having a humeral-facing side and a scapula-facing side, thebase component defining a bearing surface defined on the humeral-facingside. The glenoid assembly further includes a first peg extending fromthe scapula-facing side of the base component, the first peg including afirst shaft with a first passageway extending through the first shaft,and a second peg extending from the scapula-facing side of the basecomponent, the second peg including a second shaft with a secondpassageway extending through the second shaft, and the first peg and thesecond peg are positioned in a non-parallel orientation with respect toeach other.

In another embodiment, an implantation method includes creating a firstbore and a second bore in a glenoid region of a scapula so that a firstopening defined by the first bore and a second opening defined by thesecond bore are offset by a first distance. The method further includesproviding a glenoid component that includes (i) a base component havinga bearing surface defined on a humeral-facing side thereof, (ii) a firstpeg extending from a scapula-facing side of the base component, and(iii) a second peg extending from the scapula-facing side of the basecomponent, the first peg and the second peg being positioned innon-parallel orientation with respect to each other. The method alsoincludes flexing at least one of the first peg and the second peg sothat a first end portion of the first peg and a second end portion ofthe second peg are offset by a second distance which corresponds to thefirst distance. In addition, the method includes advancing the first endportion of the first peg and the second end portion of the second peginto the first bore and the second bore, respectively, while the firstend portion of the first peg and the second end portion of the secondpeg are offset by the second distance.

Pursuant to another embodiment of the present disclosure, there isprovided a glenoid assembly that includes a base component having ahumeral-facing side and a scapula-facing side, the base componentdefining a bearing surface defined on the humeral-facing side. Theglenoid assembly further includes a first peg extending from thescapula-facing side of the base component. In addition, the glenoidassembly includes a second peg extending from the scapula-facing side ofthe base component. The first peg and the second peg are positioned innon-parallel orientation with respect to each other. The first shaftdefines a first shaft diameter equal to FD and a first shaft lengthequal to FL. The second shaft defines a second shaft diameter equal toSD and a second shaft length equal to SL, wherein 0.14<FD/FL<0.24, andwherein 0.14<SD/SL<0.24.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view that shows a glenoid componentwhich incorporates the features of the present disclosure thereinpositioned between a scapula and a humeral head;

FIG. 2 is a perspective view of the glenoid component of FIG. 1 ;

FIG. 3 is a side elevational view of the glenoid component of FIG. 1 ;

FIG. 4 is a cross sectional view of the glenoid component of FIG. 1 ,with two stiffening members shown with the glenoid component to form aglenoid assembly;

FIG. 5 is a perspective view of an instrument grasping the glenoidcomponent of FIG. 1 , with the anchor pegs of the glenoid componentshown in their relaxed state;

FIG. 6 is a fragmentary side elevational view of the instrument of FIG.5 , and a side elevational view of the glenoid component of FIG. 5 ,with the anchor pegs of the glenoid component shown in their flexed orbent state;

FIG. 7 is a side elevational view of the glenoid assembly of FIG. 4after it is implanted in the scapula of FIG. 1 ;

FIG. 8 is a perspective view of an alternative embodiment of a glenoidcomponent and two stiffening members which collectively form analternative glenoid assembly;

FIG. 9 is a side elevational view of the glenoid component of FIG. 8 ;

FIG. 10 is a perspective view of yet another alternative embodiment of aglenoid component;

FIG. 11 is another perspective view of the glenoid component of FIG. 10along with two stiffening members which collectively form anotheralternative glenoid assembly;

FIG. 12 is a perspective view of still another alternative embodiment ofa glenoid component and two stiffening members which collectively formyet still another alternative glenoid assembly;

FIG. 13 is a side elevational view of the glenoid component of FIG. 12 ;

FIG. 14 is a fragmentary perspective view of an alternative instrumentfor grasping the glenoid component of FIG. 1 , with the instrumentapproaching the anchor pegs from a common side; and

FIG. 15 is another fragmentary perspective view of the instrument forgrasping the glenoid component of FIG. 14 , but showing the instrumentapproaching the anchor pegs from a slightly different angle incomparison to the approach shown in FIG. 14 .

DESCRIPTION OF THE PREFERRED EMBODIMENTS

While the glenoid assembly and associated method described herein issusceptible to various modifications and alternative forms, specificembodiments thereof have been shown by way of example in the drawingsand will herein be described in detail. It should be understood,however, that there is no intent to limit the glenoid assembly andassociated method to the particular forms disclosed, but on thecontrary, the intention is to cover all modifications, equivalents, andalternatives falling within the spirit and scope of the invention asdefined by the appended claims.

Glenoid Component 10 and Associated Assembly

Referring now to FIG. 1 , there is shown a glenoid component 10 that isconfigured to be implanted in a glenoid region 12 of a scapula 14. Theglenoid component 10 includes a base component 16 that defines a bearingsurface 18. The bearing surface 18 is configured to mate with a bearingsurface 20 of a humeral head 22 of a humeral prosthesis 24. While thehumeral head 22 is depicted in FIG. 1 as a prosthetic humeral headsecured to a proximal end of a humerus 26, the bearing surface 18 mayalso mate with a natural head (not shown) of the humerus 26. Also, thehumeral prosthesis 24 may be implanted in the humerus 26 using any oneof various implantation methods well known to those skilled in themedical arts. As an example, the humeral prosthesis may include a stem(not shown) that is attached to the humeral head 22 and implanted withinan intramedullary canal (not shown) of the humerus 26 in a conventionalmanner.

Turning now to FIGS. 2-4 , the glenoid component 10 is shown in moredetail. In particular, the base component 16 of the glenoid component 10has a humeral-facing side 28 and a scapula-facing side 30. The bearingcomponent 18 is defined on the humeral-facing side 28. The glenoidcomponent 10 further includes an anchor peg 32 and another anchor peg34. The anchor peg 32 has a distal end portion 32E, while the anchor peg34 has a distal end portion 34E. The anchor pegs 32, 34 extend from thescapula-facing side 30 in non-parallel orientation with respect to eachother as shown in FIGS. 2-4 . Specifically, the non-parallel orientationis a diverging orientation with respect to each other. The glenoidcomponent 10 additionally includes a stabilizing or anti-rotation peg 44and another stabilizing or anti-rotation peg 46. The stabilizing pegs44, 46 extend from the scapula-facing side 30 in parallel orientationwith respect to each other as shown in FIGS. 2-4 .

In a preferred embodiment, the glenoid component 10 is constructed as aone-piece member of synthetic polymeric material, with the basecomponent 16, the anchor pegs 32, 34, and the stabilizing pegs 44, 46integrally formed together as shown in FIGS. 2-4 . The preferredmaterial used to make the glenoid component 10 is ultra-high molecularweight polyethylene, although any known biocompatible material may beused.

The anchor peg 32 includes a shaft 36 and a number of fins 38 extendingradially from the shaft 36, while the anchor peg 34 includes a shaft 40and a number of fins 42 extending radially from the shaft 40. The shaft36 of the anchor peg 32 defines a first shaft diameter equal to FD and afirst shaft length equal to FL, while the shaft 40 of the anchor peg 34defines a second shaft diameter equal to SD and a second shaft lengthequal to SL.

Preferably, 15.0 mm<FL<25.0 mm. More preferably, 19.0 mm<FL<21.0 mm. Andmost preferably FL is equal 19.6 mm. Similarly, preferably, 15.0mm<SL<25.0 mm. More preferably, 19.0 mm<SL<21.0 mm. And most preferablySL is equal to 19.6 mm.

Preferably, 3.0 mm<FD<4.5 mm. More preferably, 3.3 mm<FD<4.3 mm. Andmost preferably FD is equal 3.8 mm. Similarly, preferably, 3.0 mm<SD<4.5mm. More preferably, 3.3 mm<SD<4.3 mm. And most preferably SD is equal3.8 mm.

The ratio of the first shaft diameter to the first shaft length isFD/FL, while the ratio of the second shaft diameter to the second shaftlength is SD/SL. Preferably, 0.14<FD/FL<0.24. More preferably,0.16<FD/FL<0.22. And most preferably FD/FL is equal to 0.19. Similarly,preferably, 0.14<SD/SL<0.24. More preferably, 0.16<SD/SL<0.22. And mostpreferably SD/SL is equal to 0.19.

It should be appreciated the values of FD, FL, SD, and SL are selectedso that the anchor pegs 32, 34 possess a flexible quality. This isespecially true when the glenoid component 10 is made of an ultra-highmolecular weight polyethylene material.

In order to enhance the flexibility of the anchor pegs 32, 34, theglenoid component is further configured to possess a passageway 48 andanother passageway 50. As can be seen in FIGS. 2 and 4 , the passageway48 extends through the shaft 36 of the peg 32, and the passageway 50extends through the shaft 38 of the peg 34. Both the passageway 48 andthe passageway 50 further extend through the base component 16 as shownin FIG. 4 . A pair of stiffening members 52, 54 are configured to berespectively received within the passageways 48, 50. The stiffeningmembers 52, 54 are both preferably elongate metal pins having lengthsrespectively equal to the length of passageways 48, 50. As an example,each pin 52, 54 may be made from stainless steel. The stiffening members52, 54 are intended to be inserted into the passageways 48, 50 after theglenoid component 10 is implanted into the scapula of a patient as willbe discussed in more detail below.

The first passageway 48 has a first width FW, while the secondpassageway 50 has a second width SW. Preferably, 0.6 mm<FW<0.8 mm. Mostpreferably, FW is equal to 0.7 mm. Similarly, preferably, 0.6 mm<SW<0.8mm. Most preferably, SW is equal to 0.7 mm. It should be appreciatedthat the diameter of the pins 52, 54 are respectively equal to FW, SW(or are slightly less than FW, SW) so that upon insertion of the pins52, 54, into the passageways 48, 50, respectively, the pins will beretained therein in a friction fit manner. Note that slight elasticdeformation of the material defining the sidewalls of the passageways48, 50 will aid in retaining pins 52, 54 within the passageways 48, 50.

Implantation Method

A method of implanting the glenoid component 10 and associated partswill be described with reference to FIGS. 1 and 5-7 . Initially, a bore56, a bore 58, a bore 60, and a bore 62 are drilled in the scapula 14 inthe glenoid region 12 as shown in FIG. 1 . The bores 56, 58, 60, and 62are created to substantially correspond to the angular orientations,lengths, and diameters of the pegs 32, 34, 44, 46 in their relaxed stateas shown in FIGS. 1-5 . Note that an opening 56A defined by the bore 56and an opening 58A defined by the bore 58 are offset by a first distanceD1 (see FIG. 1 ). The pegs 32, 34, 44, 46 will be ultimately advancedinto the bores later in the procedure. Note that due to the non-parallelorientation the anchor pegs 32, 34, these pegs will have to be flexedprior to insertion of their distal end portions 32E, 34E into the boreopenings 56A, 58A. Significantly, in the relaxed state of the pegs 32,34 of the glenoid component 10, the distal end portion 32E of the peg 32is offset from the distal end portion 34E of the peg 34 by a distance D2(see FIG. 3 ) which is significantly greater than D1. Any attempt tosimultaneously advance the end portions 32E, 34E of the pegsrespectively into the openings 56A, 58A would be unsuccessful since theoffset distance D2 of the end portions 32E, 34E does not correspond tothe offset distance D1 of the openings 56A, 58A. What is meant herein bythe term “correspond” or “corresponds” with respect to the discussion ofdistances (e.g. distances D1, D2, and D3 (discussed later)) is that twodistances correspond with each other if the two distances are similarenough to enable simultaneous advancement of the distal end portions32E, 34E into the openings 56A, 58A so that the pegs 32, 34 may berespectively inserted into bores 56, 58. On the other hand, what ismeant herein by the phrase “do not correspond” with respect to thediscussion of distances (e.g. distances D1, D2, and D3 (discussedlater)) is that two distances do not correspond with each other if thetwo distances are dissimilar enough to prevent simultaneous advancementof the distal end portions 32E, 34E into the openings 56A, 58A so thatthe pegs 32, 34 cannot be respectively inserted into bores 56, 58.

Thus, the next step of the procedure is to flex the peg 32 and the peg34 so that the first end portion 32E of the first peg 32 and the secondend portion 34E of the second peg 34 are offset by a distance D3 (seeFIG. 6 ) which corresponds to the distance D1. The flexing step isperformed when the glenoid component 10 is spaced apart from the scapula14. With the end portions 32E, 34E positioned so that they are offset bythe distance D3 as shown in FIG. 6 , the end portion 32E of the firstpeg 32 and the end portion 34E of the second peg 34 are simultaneouslyadvanced through the opening 56A and into the bore 56 and through theopening 58A and into the bore 58A, respectively. Then, the first peg 32and the second peg 34 are further advanced into the first bore 56 andthe second bore 58, respectively, until the scapula-facing side 30 ofthe base component 16 contacts the scapula 14 in the glenoid region 12as shown in FIG. 7 . Note that upon complete advancement of the pegs 32,34 into the bores 56, 58, the pegs 32, 34 assume their relaxed state asshown in FIG. 7 .

One preferred manner of performing the flexing step includes the use ofan instrument 64 which is shown in FIGS. 5-6 . The instrument 64includes an elongate member 66 and an elongate member 67. The elongatemember 66 includes a first handle end portion 68, an opposite firstcontact end portion 70 configured to contact the peg 32, and a firstintermediate portion 72 interposed therebetween. The second elongatemember 67 includes a second handle end portion 74, an opposite secondcontact end portion 76 configured to contact the second peg 34, and asecond intermediate portion 78 interposed therebetween. The firstintermediate portion 72 is pivotably coupled to the second intermediateportion 78. It should be appreciated that movement of the first handleend portion 68 and the second handle end portion 74 towards each othercauses the first contact end portion 70 and the second contact endportion 76 to move towards each other.

Thus, according to this preferred manner of performing the flexing step,the following is performed. Firstly, the first contact end portion 70 ispositioned in contact with the first peg 32 and the second contact endportion 76 is positioned in contact with the second peg 34 as shown inFIG. 5 . Note that FIG. 5 shows the pegs 32, 34 of the glenoid component10 in their relaxed state in which the distal end portion 32E of the peg32 is offset from the distal end portion 34E of the peg 34 by a distanceD2 (see also FIG. 3 ). Then, the first handle end portion 68 and thesecond handle end portion 74 are moved towards each other by a medicalpersonnel's hand so as to cause the first end portion 32E of the firstpeg 32 and the second end portion 34E of the second peg 34 to movetowards each other until the end portions 32E, 34E are offset by thedistance D3 as shown in FIG. 6 .

Pursuant to an alternative manner of performing the flexing step, thefollowing is performed. A first finger 80 (shown in phantom in FIG. 6 )of a hand of a medical personnel is positioned in contact with the firstpeg 32 and a second finger 82 (shown in phantom in FIG. 6 ) of the handis positioned in contact with the second peg 34. Then, the first finger80 and the second finger 82 are moved towards each other so as to causethe first end portion 32E of the first peg 32 and the second end portion34E of the second peg 34 to move towards each other until the endportions 32E, 34E are offset by the distance D3 as shown in FIG. 6 .

Next, after full receipt of the pegs 32, 34 within the bores 56, 58 asshown in FIG. 7 , the pins 52, 54 are advanced into the passageways 48,50 in the direction of arrows 84, 86 as shown in FIG. 4 . In particular,the pin 52 is advanced within the passageway 48 in the direction ofarrow 84 until a distal end 52D of the pin 52 arrives at the distal end48D of the passageway 48. Similarly, the pin 54 is advanced within thepassageway 50 in the direction of arrow 86 until a distal end 54D of thepin 54 arrives at the distal end 50D of the passageway 50. With the pins52, 54 positioned within the passageways 48, 50, the pegs 52, 54 possessa relatively stiff configuration in comparison to the stiffness of thepegs 52, 54 without the presence of the pins 52, 54 within thepassageways 48, 50.

FIG. 7 shows a CT image of the glenoid component 10 after it isimplanted in the glenoid region 12 of the scapula 14 in accordance withthe above-identified procedure. In particular, the scapula-facing side30 of the base component 16 is shown contacting the scapula 14. Further,the peg 32 is shown located within the bore 56, while the peg 34 isshown located within the bore 58. In addition, the pin 52 is locatedwithin the passageway 48, while the pin 54 is located within thepassageway 50. (Note, for clarity of viewing, the pins 52, 54 andpassageways 48, 50 are not shown in FIG. 7 )

Glenoid Component 100 and Associated Assembly

FIGS. 8 and 9 show an alternative embodiment of a glenoid component 100that is configured, used, and implanted in the exact same manner as theglenoid component 10 of FIGS. 1-7 , except for the followingdistinctions in structure and implantation. The only difference betweenthe structures of the glenoid components 10, 100 is that the glenoidcomponent 100 does not include any stabilizing or anti-rotation pegs(similar to stabilizing pegs 44, 46 of the glenoid component 10). Thus,an associated distinction in the manner of implanting the glenoidcomponent 100 in the glenoid region 12 of the scapula 14 (in comparisonto implantation of the glenoid component 10) is that bores 60, 62 (seeFIG. 1 ) do not have to be created in the scapula 14.

Note other parts of the glenoid component 100 are shown in FIGS. 8 and 9. Due to the similarity in configuration of the glenoid component 10 andthe glenoid component 100, like numbers are used to describe bothglenoid components, with the exception that a single prime symbol isincluded after each of the various reference numerals indicating variousportions of the glenoid component 100 and associated parts. For example,reference numerals 32, 34 are used for indicating the anchor pegs of theglenoid component 10, while the reference numerals 32′, 34′ are used forindicating the anchor pegs of the glenoid component 100.

As an alternative to the glenoid component 100, instead of configuringthe glenoid component to have diverging anchor pegs (e.g. anchor pegs32′, 34′), the alternative glenoid component may have converging anchorpegs (not shown). The angular orientation of such converging anchor pegsmay be the mirror image of the divergent anchor pegs 32′, 34′. It shouldbe appreciated that an alternative instrument (somewhat like instrument64″) would need to be designed so that movement of the first handle endportion 68′ and the second handle end portion 74′ towards each othercauses the distal end portions of the converging anchor pegs to moveaway from each other until such end portions are offset by the distanceD3 (see, e.g., FIG. 6 ). Also, the bores 56′, 58′ would have to bedrilled in the scapula to substantially correspond to the angularorientations of the converging pegs in their relaxed state.

Glenoid Component 200 and Associated Assembly

FIGS. 10 and 11 show a further alternative embodiment of a glenoidcomponent 200 that is configured, used, and implanted in the exact samemanner as the glenoid component 100 of FIGS. 8-9 , except for thefollowing distinction in structure and implantation. The sole differencebetween the structures of the glenoid components 100, 200 is that thepegs 32″, 34″ of the glenoid component 200 possess differing angularorientations in comparison to the pegs 32′, 34′ of the glenoid component100. The particular angular orientations of the pegs 32″, 34″ of theglenoid component 200 is shown in FIGS. 10-11 . Thus, an associateddistinction in the manner of implanting the glenoid component 200 in theglenoid region 12 of the scapula 14 (in comparison to the implantationof the glenoid component 100) is that bores 56, 58 (see FIG. 1 ) have tobe drilled in the scapula to substantially correspond to the angularorientations of the pegs 32″, 34″ in their relaxed state which is shownin FIGS. 10-11 . A further associated distinction in the manner ofimplanting the glenoid component 200 in the glenoid region 12 of thescapula 14 (in comparison to the implantation of the glenoid component100) is that the pegs 32″, 34″ would have to be flexed in differentdirections so that the first end portion 32E″ of the first peg 32″ andthe second end portion 34E″ of the second peg 34″ are offset by thedistance D3 (see FIG. 6 ) which corresponds to the distance D1. As withthe implantation method described in connection with the glenoidcomponent 10, the pegs 32″, 34″ could flexed by fingers of a person'shand or an instrument 64″. Of course, the instrument 64″ would need tobe designed so that movement of the first handle end portion 68″ and thesecond handle end portion 74″ towards each other by a medicalpersonnel's hand causes the first end portion 32E″ of the first peg 32″and the second end portion 34E″ of the second peg 34″ to move away fromeach other until the end portions 32E″, 34E″ are offset by the distanceD3 (see, e.g., FIG. 6 ).

Other parts of the glenoid component 200 are shown in FIGS. 10-11 . Aswas similarly noted with respect to FIGS. 8-9 above, due to thesimilarity in configuration of the glenoid component 200 and the glenoidcomponent 100, like numbers are used to describe both glenoidcomponents, with the exception that a double prime symbol is includedafter each of the various reference numerals indicating various portionsof the glenoid component 200 and associated parts. For example,reference numerals 32′, 34′ are used for indicating the anchor pegs ofthe glenoid component 100, while the reference numerals 32″, 34″ areused for indicating the anchor pegs of the glenoid component 200.

Glenoid Component 300 and Associated Assembly

FIGS. 12 and 13 show yet another alternative embodiment of a glenoidcomponent 300 that is configured, used, and implanted in the exact samemanner as the glenoid component 200 of FIGS. 10-11 , except for thefollowing distinctions in structure and implantation. A first differencebetween the structures of the glenoid components 200, 300 is that theglenoid component 300 includes a stabilizing peg 302 that is configuredexactly as either of the stabilizing pegs 44, 46 of FIGS. 1-7 . However,the stabilizing peg 302 extends from the scapula-facing side 30′″ of thebase component 16′″ at a location that is centrally located on thescapula-facing side 30′″. Another difference between the structures ofthe glenoid components 200, 300 is that the pegs 32″, 34′″ of theglenoid component 300 possess differing angular orientations incomparison to the pegs 32″, 34″ of the glenoid component 200. Theparticular angular orientations of the pegs 32″, 34′″ of the glenoidcomponent 300 is shown in FIGS. 12-13 . Thus, an associated distinctionin the manner of implanting the glenoid component 300 in the glenoidregion 12 of the scapula 14 (in comparison to the implantation of theglenoid component 200) is that the bores 56, 58 (see FIG. 1 ) have to bedrilled in the scapula to substantially correspond to the angularorientations of the pegs 32′″, 34′″ in their relaxed state which isshown in FIGS. 12-13 . Further, a bore (not shown) would have to bedrilled in the scapula to substantially correspond to the angularorientation, length, and diameter of the peg 302 which is shown in FIGS.12-13 . A further associated distinction in the manner of implanting theglenoid component 300 in the glenoid region 12 of the scapula 14 (incomparison to the implantation of the glenoid component 200) is that thepegs 32′, 34″ would have to be flexed in different directions so thatthe first end portion 32E′″ of the first peg 32′″ and the second endportion 34E′″ of the second peg 34″ are offset by the distance D3 (seeFIG. 6 ) which corresponds to the distance D1. As with the implantationmethod described in connection with the glenoid component 10, the pegs32′, 34″ could flexed by fingers of a person's hand or an instrument64″. Of course, the instrument 64′″ would need to be redesigned so thatmovement of the first handle end portion 68′ and the second handle endportion 74″ towards each other by a medical personnel's hand causes thefirst end portion 32E′″ of the first peg 32′ and the second end portion34E′″ of the second peg 34′″ to move with respect to each other untilthe end portions 32E″, 34E′″ are offset by the distance D3 (see, e.g.,FIG. 6 ).

As with the alternative glenoid components 100, 200, other parts of theglenoid component 300 are shown in FIGS. 12-13 . As was similarly notedwith respect to FIGS. 10-11 above, due to the similarity inconfiguration of the glenoid component 300 and the glenoid component200, like numbers are used to describe both glenoid components, with theexception that a triple prime symbol is included after each of thevarious reference numerals indicating various portions of the glenoidcomponent 300 and associated parts. For example, reference numerals 32″,34″ are used for indicating the anchor pegs of the glenoid component200, while the reference numerals 32′, 34′″ are used for indicating theanchor pegs of the glenoid component 300.

Instrument 400

FIGS. 14 and 15 show an alternative embodiment of an instrument 400 thatis used in place of the instrument 64 (see FIGS. 5-6 ) to perform theflexing step discussed above. The instrument 400 is similar inconstruction and operation to the instrument 64 in the sense that it isa generally scissors-shaped device. Also, the instrument 400 is used inthe exact same manner as the instrument 64 as discussed above to carryout the implantation of the glenoid component 10, with one exception. Inparticular, as shown in FIG. 14 , the two distal arm segments (i.e.distal arm segments 402 and 404) approach the anchor pegs 32, 34 from acommon side of the glenoid component 10 during an implantation procedureinstead of approaching from opposite sides (as shown in FIGS. 5-6 inconnection with the use of instrument 64). FIG. 15 also shows theinstrument 400 approaching the anchor pegs 32, 34 from a common sidesimilar to FIG. 14 , but from a slightly different direction. It shouldbe appreciated that many manners of approaching the anchor pegs 32, 34with an instrument (e.g. instrument 64, 400) are possible duringimplantation of the glenoid component 10.

There is a plurality of advantages arising from the various features ofeach of the embodiments of the glenoid assembly and associated methoddescribed herein. It will be noted that alternative embodiments of theglenoid assembly and associated method may not include all of thefeatures described yet still benefit from at least some of theadvantages of such features. Those of ordinary skill in the art mayreadily devise their own implementations of the glenoid assembly andassociated method that incorporate one or more of the features and fallwithin the spirit and scope of the present invention as defined by theappended claims.

What is claimed is:
 1. A method of implanting a glenoid assembly,comprising: forming a first bore in a glenoid region of a scapula;inserting a first peg of a glenoid component into the first bore; andplastically deforming a first passageway within the first peg, while thefirst peg is inserted into the first bore, by inserting a firststiffening pin into the first passageway.
 2. The method of claim 1,further comprising: forming a second bore in the glenoid region of thescapula; inserting a second peg of the glenoid component into the secondbore; and plastically deforming a second passageway within the secondpeg, while the second peg is inserted into the second bore, by insertinga second stiffening pin into the second passageway.
 3. The method ofclaim 1, further comprising: flexing the first peg in a direction towarda second peg to a flexed position, before inserting the first peg of theglenoid component into the first bore, wherein inserting the first pegof the glenoid component into the first bore comprises: partiallyinserting the first peg of the glenoid component into the first borewhile the first peg is in the flexed position.
 4. The method of claim 3,wherein inserting the first peg of the glenoid component into the firstbore further comprises: releasing the first peg from the flexed positionwith the first peg partially within the first bore; and fully insertingthe first peg into the first bore after releasing the first peg from theflexed position.
 5. The method of claim 4, wherein: a shaft of the firstpeg defines a shaft diameter equal to FD and a shaft length equal to FL;and0.14<FD/FL<0.24.
 6. The method of claim 5, wherein 15.0 mm<FL<25.0 mm.7. The method of claim 6, wherein:19.0 mm<FL<21.0 mm;0.16<FD/FL<0.22.
 8. The method of claim 4, wherein: the first passagewayhas a first minimum unbiased width (FUW); and0.6 mm<FUW<0.8 mm.
 9. The method of claim 3, wherein partially insertingthe first peg of the glenoid component into the first bore while thefirst peg is in the flexed position comprises: inserting at least onefin of the first peg into the first bore.
 10. The method of claim 3,wherein flexing the first peg in a direction toward a second peg to aflexed position, before inserting the first peg of the glenoid componentinto the first bore, comprises: applying pressure to the first peg at alocation between a fin of the first peg and a scapula-facing side of abase component of the glenoid component.
 11. The method of claim 1,wherein: the first passageway extends through of a base component of theglenoid component; and inserting the first stiffening pin into the firstpassageway includes inserting the first pin through the base componentand into the first passageway.